These navigation systems are actually labelled segments, which comprise of the entire process of data requests, retrieval and transmitting. Three segments of “Global Positioning System” include space segment, control segment and user segment. Out of the three segments, space segments is probably the best, most advanced and most expensive. Satellites that initiate the functionality of GPS are around 11,000 nautical miles far from each other. Moreover, every satellite has its own orbit and a clock that maintains data transmission.
GPS satellites circle turn around the earth for two times a day in precise circles for transmitting signal information. Global Positioning System receivers collect this information and make use of triangulation for calculating the exact location of users. Essentially, GPS receiver evaluates the time gap between transmission of signal and its receipt. This time gap divulges the fact about the distance of the satellite from the receiver. Today, the receiver can determine the position of the user and can display it on an electronic map by measuring the distance from a few satellites. This receiver must be protected onto signals of minimum three satellites for calculating 2D position and tracking movement of users.
With four or even more visible satellites, the receiver can determine the 3D position of the user, both latitude and longitude wise. Right now, the receivers are considered the most accurate source because of their parallel and multi channel designs. Twelve similar channel receivers of Garmin are quick to catch onto satellites when they are turned on for the first time. Moreover, these GPS receivers maintain strong and well- built locks in dense fog and urban location having tall buildings. Environmental factors and technical errors have a great impact on the accuracy of receivers. Once the position of the user is determined, the receiver can easily calculate other decisive information like bearing track, sunrise or sunset time, speed and trip distance.
The latest receiver of Garmin together with WAAS or “Wide Area Augmentation System” has the potency to improve the accuracy of the system. The good thing is that no additional charges or equipment are required to acquire the benefits of WAAS. This system is composed of towers, which receive signal from GPS and transmit it to the correct signal with the use of beacon transmitter. In addition to GPS, users must have different beacon receivers to get the correct signal. GPS system uses a built-in model, which determines average delay to moderately correct time gaps.